Infrared spectroscopy analysis of hemp (Cannabis sativa) after selective delignification by Bjerkandera sp. at different nitrogen levels

José Dorado, Gonzalo Almendros, Jim A. Field, Reyes Sierra-Alvarez

Research output: Contribution to journalArticle

28 Scopus citations

Abstract

Fourier-transform infrared (FT-IR) spectroscopy has been used to monitor changes in C/N-modified lignocellulosic substrates from Cannabis sativa L. in a 7-week solid-state fermentation with the white-rot fungus Bjerkandera sp. strain BOS55. The microbial transformation of hemp was considered as a pretreatment to pulping processes in paper industries. Special emphasis was paid on the N-content of the substrate, which was modified by: (i) external ammonium inputs, (ii) water extraction, and (iii) protease treatment. Selective delignification in the N-limited media was observed. The most diagnostic FT-IR spectral bands in relation to changes in the lignocellulosic substrate were those corresponding to alkyl structures (2920, 1460 cm-1), carboxyl groups (1720 cm-1), amides (1650, 1540 cm-1) and carbohydrate (mainly 1030 cm-1). Simple and multiple regression functions revealed the potential of FT-IR in accurately reflecting substrate composition features previously determined by wet chemical methods. Correspondence analysis suggests C/N-dependent degradation patterns, and discriminant analysis confirmed that the differences between N-limited, N-enriched and the original substrate were significant (P < 0.05) in terms of the intensities of five FT-IR diagnostic bands (1030, 1130, 1270, 1540 and 1650 cm-1). The results suggest that, in the system studied, the FT-IR spectroscopy is a reliable alternative to wet chemical analyses in the routine monitoring of the success of the biologic process since it reflects both qualitative and quantitative changes and it is very sensitive to lignin alteration and to carbohydrate and protein concentration.

Original languageEnglish (US)
Pages (from-to)550-559
Number of pages10
JournalEnzyme and Microbial Technology
Volume28
Issue number6
DOIs
StatePublished - Apr 5 2001
Externally publishedYes

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Keywords

  • Bjerkandera sp. strain BOS55
  • C/N-modified substrate
  • FT-IR spectroscopy
  • Fiber raw material
  • Solid-state fermentation
  • Stemwood biodegradation

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Biochemistry
  • Applied Microbiology and Biotechnology

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